Immunizations with diverse sarbecovirus receptor-binding domains elicit SARS-CoV-2 neutralizing antibodies against a conserved site of vulnerability.

Viral mutations are an emerging concern in reducing SARS-CoV-2 vaccination efficacy. Second-generation vaccines will need to elicit neutralizing antibodies against sites that are evolutionarily conserved across the sarbecovirus subgenus. Here, we immunized mice containing a human antibody repertoire with diverse sarbecovirus receptor-binding domains (RBDs) to identify antibodies targeting conserved sites of vulnerability. Antibodies with broad reactivity against diverse clade B RBDs targeting the conserved class 4 epitope, with recurring IGHV/IGKV pairs, were readily elicited but were non-neutralizing. However, rare class 4 antibodies binding this conserved RBD supersite showed potent neutralization of SARS-CoV-2 and all variants of concern. Structural analysis revealed that the neutralizing ability of cross-reactive antibodies was reserved only for those with an elongated CDRH3 that extends the antiparallel beta-sheet RBD core and orients the antibody light chain to obstruct ACE2-RBD interactions. These results identify a structurally defined pathway for vaccine strategies eliciting escape-resistant SARS-CoV-2 neutralizing antibodies.

Periclase deforms more slowly than bridgmanite under mantle conditions.

Transport of heat from the interior of the Earth drives convection in the mantle, which involves the deformation of solid rocks over billions of years. The lower mantle of the Earth is mostly composed of iron-bearing bridgmanite MgSiO3 and approximately 25% volume periclase MgO (also with some iron). It is commonly accepted that ferropericlase is weaker than bridgmanite1. Considerable progress has been made in recent years to study assemblages representative of the lower mantle under the relevant pressure and temperature conditions2,3. However, the natural strain rates are 8 to 10 orders of magnitude lower than in the laboratory, and are still inaccessible to us. Once the deformation mechanisms of rocks and their constituent minerals have been identified, it is possible to overcome this limitation thanks to multiscale numerical modelling, and to determine rheological properties for inaccessible strain rates. In this work we use 2.5-dimensional dislocation dynamics to model the low-stress creep of MgO periclase at lower mantle pressures and temperatures. We show that periclase deforms very slowly under these conditions, in particular, much more slowly than bridgmanite deforming by pure climb creep. This is due to slow diffusion of oxygen in periclase under pressure. In the assemblage, this secondary phase hardly participates in the deformation, so that the rheology of the lower mantle is very well described by that of bridgmanite. Our results show that drastic changes in deformation mechanisms can occur as a function of the strain rate.

Long-term stability in the circumpolar foraging range of a Southern Ocean predator between the eras of whaling and rapid climate change.

Assessing environmental changes in Southern Ocean ecosystems is difficult due to its remoteness and data sparsity. Monitoring marine predators that respond rapidly to environmental variation may enable us to track anthropogenic effects on ecosystems. Yet, many long-term datasets of marine predators are incomplete because they are spatially constrained and/or track ecosystems already modified by industrial fishing and whaling in the latter half of the 20th century. Here, we assess the contemporary offshore distribution of a wide-ranging marine predator, the southern right whale (SRW, Eubalaena australis), that forages on copepods and krill from ~30°S to the Antarctic ice edge (>60°S). We analyzed carbon and nitrogen isotope values of 1,002 skin samples from six genetically distinct SRW populations using a customized assignment approach that accounts for temporal and spatial variation in the Southern Ocean phytoplankton isoscape. Over the past three decades, SRWs increased their use of mid-latitude foraging grounds in the south Atlantic and southwest (SW) Indian oceans in the late austral summer and autumn and slightly increased their use of high-latitude (>60°S) foraging grounds in the SW Pacific, coincident with observed changes in prey distribution and abundance on a circumpolar scale. Comparing foraging assignments with whaling records since the 18th century showed remarkable stability in use of mid-latitude foraging areas. We attribute this consistency across four centuries to the physical stability of ocean fronts and resulting productivity in mid-latitude ecosystems of the Southern Ocean compared with polar regions that may be more influenced by recent climate change.

Characterization of an HNA aptamer suggests a non-canonical G-quadruplex motif.

Nucleic acids not only form the basis of heredity, but are increasingly a source of novel nano-structures, -devices and drugs. This has spurred the development of chemically modified alternatives (xeno nucleic acids (XNAs)) comprising chemical configurations not found in nature to extend their chemical and functional scope. XNAs can be evolved into ligands (XNA aptamers) that bind their targets with high affinity and specificity. However, detailed investigations into structural and functional aspects of XNA aptamers have been limited. Here we describe a detailed structure-function analysis of LYS-S8-19, a 1',5'-anhydrohexitol nucleic acid (HNA) aptamer to hen egg-white lysozyme (HEL). Mapping of the aptamer interaction interface with its cognate HEL target antigen revealed interaction epitopes, affinities, kinetics and hot-spots of binding energy similar to protein ligands such as anti-HEL-nanobodies. Truncation analysis and molecular dynamics (MD) simulations suggest that the HNA aptamer core motif folds into a novel and not previously observed HNA tertiary structure, comprising non-canonical hT-hA-hT/hT-hT-hT triplet and hG4-quadruplex structures, consistent with its recognition by two different G4-specific antibodies.

Genetic and structural basis of the human anti-α-galactosyl antibody response.

Humans lack the capacity to produce the Galα1-3Galß1-4GlcNAc (α-gal) glycan, and produce anti-α-gal antibodies upon exposure to the carbohydrate on a diverse set of immunogens, including commensal gut bacteria, malaria parasites, cetuximab, and tick proteins. Here we use X-ray crystallographic analysis of antibodies from α-gal knockout mice and humans in complex with the glycan to reveal a common binding motif, centered on a germline-encoded tryptophan residue at Kabat position 33 (W33) of the complementarity-determining region of the variable heavy chain (CDRH1). Immunoglobulin sequencing of anti-α-gal B cells in healthy humans and tick-induced mammalian meat anaphylaxis patients revealed preferential use of heavy chain germline IGHV3-7, encoding W33, among an otherwise highly polyclonal antibody response. Antigen binding was critically dependent on the presence of the germline-encoded W33 residue for all of the analyzed antibodies; moreover, introduction of the W33 motif into naive IGHV3-23 antibody phage libraries enabled the rapid selection of α-gal binders. Our results outline structural and genetic factors that shape the human anti-α-galactosyl antibody response, and provide a framework for future therapeutics development.

Structural and functional characterization of capsid binding by anti-AAV9 monoclonal antibodies from infants after SMA gene therapy.

Success in the treatment of infants with spinal muscular atrophy (SMA) underscores the potential of vectors based on adeno-associated virus (AAV). However, a major obstacle to the full realization of this potential is pre-existing natural and therapy-induced anti-capsid humoral immunity. Structure-guided capsid engineering is one possible approach to surmounting this challenge but necessitates an understanding of capsid-antibody interactions at high molecular resolution. Currently, only mouse-derived monoclonal antibodies (mAbs) are available to structurally map these interactions, which presupposes that mouse and human-derived antibodies are functionally equivalent. In this study, we have characterized the polyclonal antibody responses of infants following AAV9-mediated gene therapy for SMA and recovered 35 anti-capsid mAbs from the abundance of switched-memory B (smB) cells present in these infants. For 21 of these mAbs, seven from each of three infants, we have undertaken functional and structural analysis measuring neutralization, affinities, and binding patterns by cryoelectron microscopy (cryo-EM). Four distinct patterns were observed akin to those reported for mouse-derived mAbs, but with early evidence of differing binding pattern preference and underlying molecular interactions. This is the first human and largest series of anti-capsid mAbs to have been comprehensively characterized and will prove to be powerful tools for basic discovery and applied purposes.

Diversity of mitochondrial DNA in 3 species of great whales before and after modern whaling.

The 20th century commercial whaling industry severely reduced populations of great whales throughout the Southern Hemisphere. The effect of this exploitation on genetic diversity and population structure remains largely undescribed. Here, we compare pre- and post-whaling diversity of mitochondrial DNA (mtDNA) control region sequences for 3 great whales in the South Atlantic, such as the blue, humpback, and fin whale. Pre-whaling diversity is described from mtDNA extracted from bones collected near abandoned whaling stations, primarily from the South Atlantic island of South Georgia. These bones are known to represent the first stage of 20th century whaling and thus pre-whaling diversity of these populations. Post-whaling diversity is described from previously published studies reporting large-scale sampling of living whales in the Southern Hemisphere. Despite relatively high levels of surviving genetic diversity in the post-whaling populations, we found evidence of a probable loss of mtDNA lineages in all 3 species. This is evidenced by the detection of a large number of haplotypes found in the pre-whaling samples that are not present in the post-whaling samples. A rarefaction analysis further supports a loss of haplotypes in the South Atlantic humpback and Antarctic blue whale populations. The bones from former whaling stations in the South Atlantic represent a remarkable molecular archive for further investigation of the decline and ongoing recovery in the great whales of the Southern Hemisphere.

Conformational diversity facilitates antibody mutation trajectories and discrimination between foreign and self-antigens.

Conformational diversity and self-cross-reactivity of antigens have been correlated with evasion from neutralizing antibody responses. We utilized single cell B cell sequencing, biolayer interferometry and X-ray crystallography to trace mutation selection pathways where the antibody response must resolve cross-reactivity between foreign and self-proteins bearing near-identical contact surfaces, but differing in conformational flexibility. Recurring antibody mutation trajectories mediate long-range rearrangements of framework (FW) and complementarity determining regions (CDRs) that increase binding site conformational diversity. These antibody mutations decrease affinity for self-antigen 19-fold and increase foreign affinity 67-fold, to yield a more than 1,250-fold increase in binding discrimination. These results demonstrate how conformational diversity in antigen and antibody does not act as a barrier, as previously suggested, but rather facilitates high affinity and high discrimination between foreign and self.

Using spatial video geonarratives to improve nursing care for people who use drugs and experience homelessness: A methodology for nurses.

BACKGROUND: People who are insecurely housed and use drugs are disproportionately affected by drug poisonings. Nurses are uniquely positioned to utilize harm reduction strategies to address the needs of the whole person. Needle debris encompasses drug paraphernalia discarded in public spaces. Studying needle debris provides a strategic opportunity to identify where drugs are being used and target public health strategies accordingly. AIM: Our aim in this article is to illustrate how spatial video geonarratives (SVG) combined GPS technology interviews, and videos of locations with needle debris, can elicit valuable data for nursing research. METHODS: Using SVG required knowledge of how to collect data wearing cameras and practice sessions were necessary. A Miufly camera worn at waist height on a belt provided the stability to walk while interviewing stakeholders. We wore the cameras and conducted go-along interviews with outreach workers, while filming the built environment. Upon completion of data collection, both the interview and GPS information were analysed using Wordmapper software. CONCLUSIONS: This methodology resulted in data presented uniquely in both a visual map and narrative. These data were richer than if a single modality had been used. These data highlighted specific contextual factors that were related to the location of needle debris, which created opportunities for nursing interventions to support people experiencing vulnerability.

Examining undergraduate student perceptions and engagement during the second year of the COVID-19 pandemic.

The objectives of this study were to understand undergraduate students' overall experiences with the transition to remote learning and understand students' level of involvement with online and in-person campus programs at the start of the COVID-19 pandemic. This paper presents the findings from a series of library focus groups conducted with undergraduate students in the summer 2021. Findings showed that students experienced parallel benefits and challenges to that of remote learning when attending online campus programs. Based on these findings this paper provides student-driven recommendations for library programming. Understanding the levels of student involvement across different types of engagement and different campus stakeholders allows for articulation of the greater implications for developing library student engagement efforts.

The impact of the work environment on the health-related quality of life of Licensed Practical Nurses: a cross-sectional survey in four work environments.

BACKGROUND: Nurses are known to have negative health outcomes related to their work. While it is acknowledged that nursing work is associated with things like back injuries and burnout, there is limited evidence as to what factors in the work environment contribute to these issues. PURPOSE: The aims of this study were to assess how Licensed Practical Nurses (LPNs) report their Health-related quality of life (HRQoL), and how nurses' health is impacted by their work environment. METHODS: These data used for analysis comes from a cross-sectional survey administered online to all LPNs in Alberta (2018). The survey collected data on the following variables: participant's demographics, the SF-36 HRQoL, Practice Environment Scale of the Nursing Work Index (PES-NW) and the CD-RISC measure of resilience. The beta distribution was used to model HRQoL outcomes. In instances where optimal health (score of '1') was observed then an extended version of beta distribution (called one-inflated beta) was applied. RESULTS: 4,425 LPNs responded to the survey. LPNs (mean age: 40) report lower scores on each SF-36 subscale than the general Canadian population aged 35-44. LPNs who work 'causal' had better physical health, (OR 1.21, CI 1.11-1.32, p = 0.000), and mental health (OR 1.22, CI 1.12-1.30, p = 0.000) than LPNs who work full time, even after controlling for resilience. LPNs' views on the adequacy of staffing and resources in their workplaces have an influence across all dimensions of health. CONCLUSION: This study suggests that improvements in the work environment could positively impact health outcomes and that adequate resourcing could support the nursing workforce.

Patient-reported symptoms and experience following Guillain-Barré syndrome and related conditions: Questionnaire development and validation.

BACKGROUND: Guillain-Barré syndrome (GBS) is a rare inflammatory peripheral nerve disorder with variable recovery. Evidence is lacking on experiences of people with GBS and measurement of these experiences. OBJECTIVE: We aimed to develop and validate an instrument to measure experiences of people with GBS. DESIGN: We used a cross-sectional design and online self-administered questionnaire survey. Question domains, based on a previous systematic review and qualitative study, covered experiences of GBS, symptom severity at each stage, healthcare and factors supporting or hindering recovery. Descriptive, exploratory factor and reliability analyses and multivariable regression analysis were used to investigate the relationships between variables of interest, explore questionnaire reliability and validity and identify factors predicting recovery. SETTING AND PARTICIPANTS: People with a previous diagnosis of GBS were recruited through a social media advert. RESULTS: A total of 291 responders, of different sexes, and marital statuses, were included, with most diagnosed between 2015 and 2019. Factor analysis showed four scales: symptoms, information provided, factors affecting recovery and care received. Positive social interactions, physical activity including physiotherapy and movement, changes made at home and immunoglobulin treatment were important for recovery. Multivariable models showed that immunoglobulin and/or plasma exchange were significant predictors of recovery. Employment and recovery factors (positive interactions, work support and changes at work or home, physical activity and therapy), though associated with recovery, did not reach statistical significance. CONCLUSION: The questionnaire demonstrated good internal reliability of scales and subscales and construct validity for people following GBS. PATIENT CONTRIBUTION: Patients were involved in developing and piloting the questionnaire.

Student, Faculty, and Coach Perspectives on Why Athletes Excel in Medical School: A Qualitative Analysis.

Phenomenon Medical schools are tasked with selecting applicants who will excel in a rigorous curriculum and successfully perform as future physicians. While many studies have assessed quantitative prematriculation data for predicting success in medical school, fewer studies have assessed for qualitative prematriculation factors influencing medical school performance. A recent study revealed that medical students with at least one year of varsity level college athletics participation outperformed their peers on United States Medical Licensing board exams and clinical clerkships. The current study sought to explore medical student, medical school faculty, and college coach perspectives about factors explaining why medical students with collegiate athletic experience succeed in medical school. Approach: In 2019, the authors conducted semi-structured interviews with medical students with collegiate athletic experience, medical school faculty with experience educating student athletes, and college coaches with experience training student athletes who matriculated into medical school. The interview transcripts were systematically coded and analyzed for themes using a grounded theory approach. Participants were recruited and interviewed until saturation of data was reached. Findings: Fifteen medical students with collegiate athletic experience, five medical school faculty, and three collegiate coaches participated in the study. Six themes were identified as important factors explaining the academic success of these students in medical school and each of these themes appeared in student, faculty, and coach interviews: goal setting, goal pursuit, and performance appraisal; development of time management, planning, and organizational skills; development of team values and teamwork skills; development of communication and interpersonal skills; acceptance of, coping strategies for, and resilient response to stress and adversity; and prioritization of personal wellness. Participants described meaningful connections between these attributes and skills, suggesting the students' development, transfer, and application of them is interrelated. Insights: In this study, academic success of medical students with collegiate athletic experience was attributed to specific skills and attributes developed during college. The grounded theory life skills transfer model can explain transfer of these attributes and skills from college to the medical school setting. Theoretical frameworks and empirical study findings from the sociology, educational psychology, sports psychology, and medical education literature provide helpful lenses for understanding why these skills and attributes confer success among student athletes in medical school. These findings offer important insights on skill development that may support the academic success of all medical students.

Supervised consumption site enables cost savings by avoiding emergency services: a cost analysis study.

BACKGROUND AND AIMS: We report on a cost analysis study, using population level data to determine the emergency service costs avoided from emergency overdose management at supervised consumption services (SCS). DESIGN: We completed a cost analysis from a payer's perspective. In this setting, there is a single-payer model of service delivery. SETTING: In Calgary, Canada, 'Safeworks Harm Reduction Program' was established in late 2017 and offers 24/7 access to SCS. The facility is a nurse-led service, available for client drop-in. We conducted a cost analysis for the entire duration of the program from November 2017 to January 2020, a period of 2 years and 3 months. METHODS: We assessed costs using the following factors from government health databases: monthly operational costs of providing services for drug consumption, cost of providing ambulance pre-hospital care for clients with overdoses who could not be revived at the facility, cost of initial treatment in an emergency department, and benefit of costs averted from overdoses that were successfully managed at the SCS. RESULTS: The proportion of clients who have overdosed at the SCS has decreased steadily for the duration of the program. The number of overdoses that can be managed on site at the SCS has trended upward, currently 98%. Each overdose that is managed at the SCS produces approximately $1600 CAD in cost savings, with a savings of over $2.3 million for the lifetime of the program. CONCLUSION: Overdose management at an SCS creates cost savings by offsetting costs required for managing overdoses using emergency department and pre-hospital ambulance services.

A Dog with an Office: The Process of Embedding a Wellness Dog Intervention in a University Setting.

Universities are places to promote the wellbeing of people who learn, work, and live within them. This article reports on an innovative, holistic, and embedded wellness dog program that was developed by the Faculty of Nursing to support the wellbeing of students, faculty, and staff. The innovation included a collaborative partnership between two faculties (the faculties of Veterinary Medicine and Nursing), and the targeted purchase, training, and socialization of a wellness dog. Pet wellness programs have the potential to be an important mental health intervention on university campuses. While the program was postponed due to COVID-19, the purpose of this article is to share processes used to create the wellness dog program, with suggestions regarding implementation and evaluation.

Discovery of 4-aminopyrimidine analogs as highly potent dual P70S6K/Akt inhibitors.

Activation of the PI3K/Akt/mTOR kinase pathway is associated with human cancers. A dual p70S6K/Akt inhibitor is sufficient to inhibit strong tumor growth and to block negative impact of the compensatory Akt feedback loop activation. A scaffold docking strategy based on an existing quinazoline carboxamide series identified 4-aminopyrimidine analog 6, which showed a single-digit nanomolar and a micromolar potencies in p70S6K and Akt enzymatic assays. SAR optimization improved Akt enzymatic and p70S6K cellular potencies, reduced hERG liability, and ultimately discovered the promising candidate 37, which exhibited with a single digit nanomolar value in both p70S6K and Akt biochemical assays, and hERG activities (IC50 = 17.4 µM). This agent demonstrated dose-dependent efficacy in inhibiting mice breast cancer tumor growth and covered more than 90% pS6 inhibition up to 24 h at a dose of 200 mg/kg po.

The First Detection of an Earthquake From a Balloon Using Its Acoustic Signature.

Extreme temperature and pressure conditions on the surface of Venus present formidable technological challenges against performing ground-based seismology. Efficient coupling between the Venusian atmosphere and the solid planet theoretically allows the study of seismically generated acoustic waves using balloons in the upper atmosphere, where conditions are far more clement. However, earthquake detection from a balloon has never been demonstrated. We present the first detection of an earthquake from a balloon-borne microbarometer near Ridgecrest, CA in July 2019 and include a detailed analysis of the dependence of seismic infrasound, as measured from a balloon on earthquake source parameters, topography, and crustal and atmospheric structure. Our comprehensive analysis of seismo-acoustic phenomenology demonstrates that seismic activity is detectable from a high-altitude platform on Earth, and that Rayleigh wave-induced infrasound can be used to constrain subsurface velocities, paving the way for the detection and characterization of such signals on Venus.

The role of mesenchymal stem/stromal cells in the acute clinical setting.

INTRODUCTION: Accumulating evidence supports the use of mesenchymal stem/stromal cells (MSCs), particularly bone marrow derived, as a safe and promising biologic therapy for promoting tissue repair and regeneration in various chronic diseases and disorders. Despite growing evidence that MSCs are potent anti-inflammatory mediators that can provide substantial benefits in acute organ injury, there are limited clinical trials utilizing MSCs in acute care settings, such as in the emergency department (ED) or intensive care unit (ICU). OBJECTIVE: This article reviews the current state of MSC-based therapeutics and further explores the untapped potential role to treat various acute, life-threating injuries in the ED and ICU. DISCUSSION: All clinical trials using MSCs in acute myocardial infarction (AMI), acute respiratory distress syndrome (ARDS), sepsis and acute kidney injury (AKI) demonstrated safety. While some also demonstrate clinical efficacy, efficacy data is inconsistent, with some studies limited by sample size, cell integrity and different dosages, necessitating further studies. CONCLUSION: MSCs are potentially promising novel biologic therapeutics for clinical application in AMI, ARDS, sepsis, AKI and COVID-19 that have demonstrated safety in all clinical trials. More rigorous clinical trials are necessary and warranted to determine the efficacy of MSCs as a novel therapeutic in an acute setting, such as the ED.

Barriers to point-of-care ultrasound utilization during cardiac arrest in the emergency department: a regional survey of emergency physicians.

INTRODUCTION: Though point-of-care ultrasound (POCUS) is recognized as a useful diagnostic and prognostic intervention during cardiac arrest (CA), critics advise caution. The purpose of this survey study was to determine the barriers to POCUS during CA in the Emergency Department (ED). METHODS: Two survey instruments were distributed to emergency medicine (EM) attending and resident physicians at three academic centers in the South Florida. The surveys assessed demographics, experience, proficiency, attitudes and barriers. Descriptive and inferential statistics along with Item Response Theory Logistic Model and the Friedman Test with Wilcoxon Signed Rank tests were used to profile responses and rank barriers. RESULTS: 206 EM physicians were invited to participate in the survey, and 187 (91%) responded. 59% of attending physicians and 47% of resident physicians reported that POCUS is performed in all their cases of CA. 5% of attending physicians and 0% of resident physicians reported never performing POCUS during CA. The top-ranked departmental barrier for attending physicians was "No structured curriculum to educate physicians on POCUS." The top-ranked personal barriers were "I do not feel comfortable with my POCUS skills" and "I do not have sufficient time to dedicate to learning POCUS." The top-ranked barriers for resident physicians were "Time to retrieve and operate the machine" and "Chaotic milieu." CONCLUSIONS: While our study demonstrates that most attending and resident physicians utilize POCUS in CA, barriers to high-quality implementation exist. Top attending physician barriers relate to POCUS education, while the top resident physician barriers relate to logistics and the machines. Interventions to overcome these barriers might lead to optimization of POCUS performance during CA in the ED.

Kawasaki Disease and Multisystem Inflammatory Syndrome in Children: An Overview and Comparison.

Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) are inflammatory conditions that present diagnostic and therapeutic challenges to the physician. Although many of their features overlap, they are two distinct conditions. KD is a febrile illness most commonly affecting children younger than five years. It manifests with prolonged fever and at least four of the following features: bilateral bulbar conjunctivitis, mucositis, diffuse maculopapular rash, extremity changes, and cervical lymphadenopathy of 1.5 cm or more in diameter. Patients with MIS-C may have many of the same manifestations but tend to have higher rates of gastrointestinal and neurocognitive symptoms and signs of shock on presentation. Both conditions are associated with cardiac sequelae, including coronary artery aneurysms, although children with MIS-C are at high risk of developing ventricular dysfunction and depressed cardiac output. Lymphocytopenia, thrombocytopenia, elevated troponin, and elevated B-type natriuretic peptide are key laboratory findings of MIS-C that can help distinguish it from KD. The use of intravenous immune globulin is well established in KD and also appears to have a role in the treatment of MIS-C. Aspirin has been used in KD for an anti-inflammatory effect, and low-dose aspirin is recommended for MIS-C to reduce the risk of thrombosis. In addition to supportive care, patients with MIS-C may benefit from immunomodulatory medications, although data on this topic are evolving.